The present disclosure relates to a pump, and more particularly to a fuel gear pump for gas turbine engines.
Fuel gear pumps are commonly used to provide fuel flow and pressure for gas turbine engines and other systems on aircrafts. The gear pump must perform over a wide system operating range and provide critical flows and pressures for various functions. Typically, these pumps receive rotational power from an accessory gearbox through a drive shaft.
In a fuel gear pump, a shaft seal is frequently used to seal internal fuel from entry into a shaft cavity. Typically, the shaft seal performance, most notably leakage, may be monitored throughout operation, where too much leakage may cause detrimental effects. In addition, the shaft seal may need to be periodically removed, examined, possibly repaired or replaced, then re-installed. Dependant on the arrangement of the unit, the shaft seal may be difficult to access, which is usually the case in a dual gear stage pump.